Very nice. Thanks Hans
Have you considered that the cutter head is a tangential acting device and that cartridges operate as an arc from their fulcrum. This suggests time/phase shifting variations dependant upon the cantilever length and physical sideways displacement. In other words it seems the contact point moves forward in time on the vinyl on an arc from the time at the centre zero position. Don't know how much of an issue this can be, although this suggests a longer cantilever to diminish this effect. I never liked the Dynavector Ruby 23R much. It had a suspiciously short cantilever.
For what its worth I'm running a Linn/Ittok with Denon 103r and a Thorens 125 Mk2/Ittok/ Audio-Technica M95ML For better or worse I have been using my own electronics for the past 40 years+. Currently the MM and MC cartridge windings are each feeding independently floating battery powered pseudo voltage to current amplifiers (being discrete bipolar devices in open loop). These feed current into a current input phono stage containing a critically stabilized multi-loop feedback network containing RIAA poles. It is decently resolved.
That happens but the bigger issue is tracking angle error that varies along the arc. Using a longer tone arm tube can help but then other factors can be made worse, such as arm resonance characteristics.
Possibly of interest: https://pspatialaudio.com/tracking angle.htm
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This well known effect called "scrubbing", happens at the Cart's Fres and causes intermodulation distortion.
See attachment below, where the blue blobs are showing +/- 10Hz and +/-20Hz IM products when playing a 1Khz test tone with a cart having its Fres at 10Hz.
Hans
Attachments
Hans,
Not clear to me scrubbing was what Heirfi was asking about. IIUC he was asking about the fact that the needle contact point travels in an arc, whereas the cutter head travels in a straight line. Therefore at some platter RPM there will be some gradual time displacement (due to physical displacement) between the arc track and the cutter head track. IOW, a slow advancement or retardation in time that gradually occurs over minutes.
OTOH, scrubbing is a more complex possibly damped resonance effect not solely a function of the arc traced out by the needle 'contact point' (where the latter term reads to me more like a simple point-contact model is being assumed).
Mark
Not clear to me scrubbing was what Heirfi was asking about. IIUC he was asking about the fact that the needle contact point travels in an arc, whereas the cutter head travels in a straight line. Therefore at some platter RPM there will be some gradual time displacement (due to physical displacement) between the arc track and the cutter head track. IOW, a slow advancement or retardation in time that gradually occurs over minutes.
OTOH, scrubbing is a more complex possibly damped resonance effect not solely a function of the arc traced out by the needle 'contact point' (where the latter term reads to me more like a simple point-contact model is being assumed).
Mark
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There have been various attempts at managing scrubbing using dampers. SME in the add-on fluid damper for the SIII arms back in the 70's, and integral in the V and optional in the IV is one approach. Townshend used a long fluid damping bath closer to the cartridge. Then there are upmarket arms with eddy current dampers near the pivot.
And the long-gone (why for heavens sake?) Shure V15IV and V that had a viscous hinged damper mounted on the stylus assembly itself (that also incorporated a carbon fiber brush). I scored a cheap V15IV with known broken stylus and replaced it with a superb Jico stylus - a perfect replica in all regards.
And the long-gone (why for heavens sake?) Shure V15IV and V that had a viscous hinged damper mounted on the stylus assembly itself (that also incorporated a carbon fiber brush). I scored a cheap V15IV with known broken stylus and replaced it with a superb Jico stylus - a perfect replica in all regards.
Skimmed a lot but Interesting stuff. The I.M. distortions appear unmentionable it appears so bad. It seems that this could, at least in part, have something to due with simultaneous signals appearing over the moving arc of the stylus as potentially changing the generator gain.
I once took a Mission 774 tonearm (with the tiny little head) and added an acrylic block on the end. The length and mass increased dramatically. This worked exceptionally well for the cartridge used. I believe it was a really low output Ortofon MC20 (couldn't afford the 30). This was before changing to an air bearing Eminent Technology arm on a Goldmund Studio. The suspension on the Goldmund was awful by they way and the arm seemingly without the moving mass needed for the Ortofon.
It would seem that the stylus shank length/angle would also contribute to the equivalent of tracking angle errors... though perhaps in a worse way.
IIUC, not exactly.
First, you might try searching the document attached at #8,723 for the word 'scrubbing'
Also, maybe some discussions on the subject of scrubbing will help clarify:
https://audiokarma.org/forums/index...m-cartridge-compliance-question-sorry.628324/
https://www.vinylengine.com/turntable_forum/viewtopic.php?f=19&t=74220&start=12
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I don’t see any problem in the movement in the transversal direction other than a small error in the tracking angle
I find it hard to believe that this can produce any measurable IM or change the generators gain.
The scrubbing on the other hand takes place over a much larger distance creating pitch changes with corresponding measurable IM product.
But it's probably better to look at the combined IM products, you want to keep them as low as possible, whether from longitudinal or transversal movement.
An Fres between 10Hz and 13Hz is seen as an optimum. Lower and the IM products increase.
Hans
The moving arc of the stylus you mention in perpendicular direction, travels only micrometers in the track being connected to a cantilever several millimeters long, a ratio of 1:1000.
I find it hard to believe that this can produce any measurable IM or change the generators gain.
The scrubbing on the other hand takes place over a much larger distance creating pitch changes with corresponding measurable IM product.
But it's probably better to look at the combined IM products, you want to keep them as low as possible, whether from longitudinal or transversal movement.
An Fres between 10Hz and 13Hz is seen as an optimum. Lower and the IM products increase.
Hans
Thinking again, I realised that the shape if a waveform may become slightly distorted because of the differing movement between cutter and cantilever, but not the pitch.
And symmetric waveform distortion leads to uneven harmonics but not to IMD.
So all IMD must be generated by scuffing and speed variations in the record because of excentricity imperfections.
Hans
And symmetric waveform distortion leads to uneven harmonics but not to IMD.
So all IMD must be generated by scuffing and speed variations in the record because of excentricity imperfections.
Hans
Arrived early, just today. Now playing DSD256 version. Wonderful music and performance. However, recording is quite clearly distorted. Thus don't know that it makes any sense to compare subtleties of space and fidelity in terms of PCM versus DSD256 when distortion effects are so quite plainly evident to begin with. For one example, the sound of piano chordal textures as conveyed through the instrument sound board are brighter, edgier, and rougher (my words for the recording's sound) as versus what a live piano sounds like.
In that context and relating to 'texture,' it may help to recall that what we perceive as beat notes are interference patterns (or 'envelopes') produced by the summing of frequencies (and not by multiplying them), hence beat notes do not result from the creation of new frequencies, at least not in an LTI system. Chordal textures, I believe, are due to the notes played plus the various beat notes associated with the resulting interference patterns. That is to say, IMHO the instrument sound is the sum of those things, notes and envelopes, perhaps combined with a little nonlinearity within the instrument itself (as well as other things such as it acoustical radiation pattern). Thus my use of the word, 'texture' in the first paragraph above.
The reason I use the particular word 'texture' in a perceptual sense comes from its usage in Auditory Scene Analysis. Maybe something more or less along the lines as described at: https://www.sciencedirect.com/science/article/pii/S0960982211011882 Anyway, I have been trying to bring together what seems to me is a large part of the relationship between perceived auditory texture and is physical production in an acoustic instrument. Opinion subject to revision without further notice, of course.
Would also note that the audible distortion in this particular recording makes it hard to really assess the adequacy of 16/44 for this type of music. IMHO, dither and quantizing noise are not significant factors relative to the more predominant audible distortion mechanisms in this case. Similar thoughts regarding other subtle live sound details which may be also be obscured.
The above having been said, performance dynamics and overall musical expression are pretty darn well intact in this recording. Doesn't sound compressed at all to me.
Bottom line, I think: A not great recording of an excellent performance event. It can be very much enjoyed for what it is (and I am enjoying it as I write), but it isn't an especially good candidate for seeing to what extent very high quality reproduction can contribute to the overall listening experience of a great performance. IOW, I might like it just as well, or perhaps like it even better in some ways, if the recording sounded closer to what it must have sounded like to actually have been there there in person
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Hierfi,
Everyone else who responded to this seems to assume that the arc you're referring to is the arc of the cartridge and arm pivoting across the record surface. I read it to refer to the arc of the playback stylus on the end of its cantilever. Which did you mean?
Hi Mark
I keep the emotionally satisfaction.
In post #8680, I wrote that tape hiss and distortion were to be found in this transfer, together with ambience information. I suggested this CD as a true to the source example, a reaction to your writing “If CD were transparent then all the imperfections of tape would be exactly as bad when played back from CD”.
At discogs there are currently 2-3 Vinyl pressings of the same () Nocturnes by Rubinstein in RCA Red Seal but I can’t see if the recording dates (*) match, as the accompanying photos are low resolution. If you are interested, you may email the sellers and ask them this information.
(*)Op.9 no 1,2,3. Op.15 no 1,2,3. Op.27 no1,2. Op32 no 1,2. Op37 no 1,2. Op48 no 1,2. Op.55 no 1,2. Op.62 no 1. Op72 no 1.
(**)Recorded: Jun 29, 30 1949. July 28, 29 1949. Sept. 26 1950
For transfer to CD with sound restoration there are other CDs to suggest.
George
Hi George,
Previously I pointed out that digital graininess on the Telarc vinyl I have is plainly audible if using an modern optical phono cartridge. On that basis would you conclude that vinyl has transparently reproduced the sound exactly as it was before being recorded to vinyl?
Or would you conclude as I did that some gross artifacts can come through on any recording medium?
Mark
Previously I pointed out that digital graininess on the Telarc vinyl I have is plainly audible if using an modern optical phono cartridge. On that basis would you conclude that vinyl has transparently reproduced the sound exactly as it was before being recorded to vinyl?
Or would you conclude as I did that some gross artifacts can come through on any recording medium?
Mark
True. But I'm interested in probing remaining problems with digital. When it can reproduce a recording of a phono output with the space intact, then maybe some of other missing stuff will be found too. That is to say, I think don't its just the vinyl space that isn't getting reproduced properly.
I was considering the arc of the cantilever as compared to a non-angle of a tangentially cutting cutter head. Tangentially cutting is equivalent to an infinite length stylus. In the case of a stationary record the contact point of cartridge with a short cantilever does not contact over the same contact points of the cutter moving tangentially across it. At the sides the short cantilever advances in time from its centre position. Alternatively if the sides are in real time a cantilever moving back to its centre is retarded in time. Don't know to whatever extent this is important but seems could be significant enough for consideration.